Neurofeedback for alcohol addiction: Changes in resting state network activity✰

Alcohol dependence continues to be a major global burden despite significant research progress and treatment development. The aim of this study was to investigate whether neurofeedback training can alter resting state fMRI activity in brain regions that play a crucial role in addiction disorders in patients with alcohol dependence. For this purpose, a total of 52 patients were recruited for the present study, randomized, and divided into an active and a sham group. Patients in the active group received three sessions of neurofeedback training. We compared the resting state data in the active group as part of the NF training on six measurement days. When comparing the results of the active group from neurofeedback day 3 with baseline 1, a significant reduction in activated voxels in the ventral attention network area was seen. This suggests that reduced activity over the course of therapy in subjects may lead to greater independence from external stimuli. Overall, a global decrease in activated voxels within all three analysed networks compared to baseline was observed in the study. The use of resting-state data as potential biomarkers, as activity changes within these networks, may be to help restore cognitive processes and alcohol abuse-related craving and emotions.

Abstract 2871: The Nanoprimer: a nanoparticle designed to transiently occupy the mononuclear phagocytic system in order to increase nanomedicine-based treatments efficacy

Introduction: Most nanomedicines are currently limited in their efficacy due to a sub-optimal biodistribution/accumulation in the target tissues. A large part of the administered dose remains useless due to the high rate of clearance by the mononuclear phagocytic system (mainly by Kupffer cells in liver). We designed a new approach based on the use of an engineered, biocompatible nanoparticle–the Nanoprimer–that is administered before the nanomedicine in order to transiently and specifically occupy the liver clearance pathways responsible for sub-optimal therapeutic bioavailability. The Nanoprimer's effect is only based on its specific physico-chemical properties, there is no active principal ingredient encapsulated in it. Here we demonstrate the ability of the Nanoprimer to redefine the bioavailability and efficacy of nanomedicines loaded with small molecules or nucleic acid. We evaluated the biodistribution and the safety of the Nanoprimer alone and of an irinotecan loaded liposome combined with the Nanoprimer.

Methods: Quantitative evaluation of the Nanoprimer's biodistribution was performed by mass spectrometry. Safety profile of the Nanoprimer was evaluated in vitro (cell viability, cytokines/interleukins expression profile, complement activation, phagoburst and phagotest on different cell lines) and in vivo, in mice, by a follow up of body weight and clinical signs, histological observations of liver, spleen and lungs and blood parameters titration, after the injection of a maximized dose of Nanoprimer. The impact of the Nanoprimer on the bioavailability and biodistribution of nanomedicines loaded with irinotecan or nucleic acids (mRNA / SiRNA) was evaluated by HPLC and fluorescence quantification, respectively. Finally, the impact of the Nanoprimer on treatment was evaluated using nanomedicines encapsulating human erythropoietin (hEPO) mRNA, Factor VII (FVII) siRNA or irinotecan.

Results: The Nanoprimer presents a rapid accumulation within liver and spleen. The Nanoprimer was well tolerated with no sign of toxicity observed using therapeutic dosage. The administration of the Nanoprimer increases systemic bioavailability of different type of nanomedicines and enhances their accumulation in target tissues. This improved bioavailability is correlated with an increased secretion of hEPO by 30%, for mRNA-loaded nanomedicines, an increased silencing of FVII by 50%, for siRNA-loaded nanomedicines, and an increased anti-tumor efficacy by 50%, for irinotecan-loaded nanomedicines.

Here, we showed the safe profile of the Nanoprimer and its ability to increase the treatment outcomes for different nature of nanomedicines. The separation of the functions ensuring the efficacy of a treatment into two distinct objects opens perspectives for designing future nanomedicines and a shift in the therapeutic paradigm.

Citation Format: Julie Devalliere, Laurence Poul, Audrey Darmon, Oceane Jibault, Maxime Bergere, Francis Mpambani, Nell Saunders, Marion Paolini, Robert Langer, Matthieu Germain. The Nanoprimer: a nanoparticle designed to transiently occupy the mononuclear phagocytic system in order to increase nanomedicine-based treatments efficacy [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2871.

Gas Chromatography Combustion Isotope Ratio Mass Spectrometry for Improving the Detection of Authenticity of Grape Must

Since ancient times, grape must and wine have been considered one of the most sophisticated matrices and, in the last few years, the continuous rise in volumes and prices of grapes and wine has encouraged fraud and adulteration in the oenological field. One of the most common adulterations is sugar addition to grape must in the form of cane or beet sugar or syrup coming from vegetable sources, such as cereals or fruits. Since 1990, the International Organisation of Vine and Wine (OIV) has issued specific official isotopic methods to fight against this practice, but they are not always effective. With the aim to develop a new method able to identify sugar addition, we compared the δ¹³C value of sugar extracted from grape must analyzed by elemental analyzer/isotope ratio mass spectrometry (EA-IRMS) to the δ¹³C value of proline analyzed by gas chromatography-combustion isotope ratio mass spectrometry (GC-C-IRMS), after extraction and derivatization. δ¹³C and δ¹⁵N of proline have also been tested as potential geographical markers. In addition, the carbon isotopic composition of two characteristic grape must sugars (myo- and scyllo-inositols) was measured by GC-C-IRMS, after derivatization, to identify the illegal correction of their concentration. On the basis of the obtained results we can conclude that the compound-specific isotope analysis represents a novel analytical tool to support and improve certification and control procedures.

Outlooks on Three-Dimensional Printing for Ocular Biomaterials Research

Given its potential for high-resolution, customizable, and waste-free fabrication of medical devices and in vitro biological models, 3-dimensional (3D) bioprinting has broad utility within the biomaterials field. Indeed, 3D bioprinting has to date been successfully used for the development of drug delivery systems, the recapitulation of hard biological tissues, and the fabrication of cellularized organ and tissue-mimics, among other applications. In this study, we highlight convergent efforts within engineering, cell biology, soft matter, and chemistry in an overview of the 3D bioprinting field, and we then conclude our work with outlooks toward the application of 3D bioprinting for ocular research in vitro and in vivo.

Efficacy of a new delivery system based on solid lipid microparticles for the oral administration of the non-conventional antioxidant IAC on a diabetes mouse model

PURPOSE

We previously showed the positive effects of the new antioxidant molecule bis(1-hydroxy-2,2,6,6-tetramethyl-4-piperidinyl)-decandioate (IAC) in reducing basal hyperglycaemia and relieving glucose intolerance in a diabetes model. However, the chemical properties of IAC did not allow an efficient oral administration, thus representing the main failing of that study. Here, we tested the effect of a new oral delivery system based on solid lipid microparticles (SLMs) in a diabetes mouse model.

METHODS

The diabetes model was induced in C57B1/6J mice using streptozotocin and nicotinamide. Only the animals that overcame the glycaemic threshold of 180 mg/dL were enrolled in the study. Diabetic animals were then randomly assigned to 4 groups (n = 9) and treated once a day for 5 consecutive weeks with IAC (50, 100, and 150 mg/kg b.w.). The control group was composed of (n = 7) healthy mice that received only the vehicle. Glucose level was weekly monitored during the treatment period and up to 3 weeks after the suspension of the treatment. Glucose tolerance and insulin-resistance test were carried out.

RESULTS

Our results showed that SLMs maintained the IAC effect in reducing basal hyperglycaemia as well as improving the insulin sensitivity and glucose tolerance.

CONCLUSION

The present study confirms that SLMs are promising drug carriers, which allow the oral administration of IAC ensuring its therapeutic efficacy. The concrete possibility to administer IAC per os represents a significant breakthrough in the putative consideration of this multi-radical scavenger in the diabetes therapeutic approach.

Nano-sized cytochrome P450 3A4 inhibitors to block hepatic metabolism of docetaxel

Most drugs are metabolized by hepatic cytochrome P450 3A4 (CYP3A4), resulting in their reduced bioavailability. In this study, we present the design and evaluation of bio-compatible nanocarriers trapping a natural CYP3A4-inhibiting compound. Our aim in using nanocarriers was to target the natural CYP3A4-inhibiting agent to hepatic CYP3A4 and leave drug-metabolizing enzymes in other organs undisturbed. In the design of such nanocarriers, we took advantage of the nonspecific accumulation of small nanoparticles in the liver. Specific targeting functionalization was added to direct nanocarriers toward hepatocytes. Nanocarriers were evaluated in vitro for their CYP3A4 inhibition capacity and in vivo for their biodistribution, and finally injected 24 hours prior to the drug docetaxel, for their ability to improve the efficiency of the drug docetaxel. Nanoparticles of poly(lactic-co-glycolic) acid (PLGA) with a hydrodynamic diameter of 63 nm, functionalized with galactosamine, showed efficient in vitro CYP3A4 inhibition and the highest accumulation in hepatocytes. When compared to docetaxel alone, in nude mice bearing the human breast cancer, MDA-MB-231 model, they significantly improved the delay in tumor growth (treated group versus docetaxel alone, percent treated versus control ratio [%T/C] of 32%) and demonstrated a major improvement in overall survival (survival rate of 67% versus 0% at day 55).

Multi-isotopic signatures of organic and conventional Italian pasta along the production chain

The variability of stable isotope ratios (δ(2) H, δ(13) C, δ(15) N, δ(18) O and δ(34) S) along the production chain of pasta (durum wheat, flour and pasta) produced by using both conventional and organic farming systems in four Italian regions in 2 years was investigated. The aim was to evaluate if and how the farming system and geographical origin affect stable isotope ratios determined along the production chain. Irrespective of the processing technology, 65% of the samples were correctly classified according to the farming system and 98% were correctly classified regarding the geographical region. When considering both farming system and geographical region simultaneously, 80% of the samples were correctly classified. The measured isotope parameters were thus primarily affected by the geographical origin. In conclusion, it is expected that the use of these parameters will allow the development of analytical control procedures that can be used to check the geographical origin of Italian organic and conventional pasta and its raw materials. Copyright © 2016 John Wiley & Sons, Ltd.

Stable isotope ratio analysis for verifying the authenticity of balsamic and wine vinegar

In this paper, we investigate whether the analysis of stable isotope ratios D/H and ¹³C/¹²C in ethanol and acetic acid and of ¹⁸O/¹⁶O in water can be applied to the ingredients of "aceto balsamico di Modena IGP" (ABM) to evaluate their authenticity. We found that impurities in the extraction solution do not affect the ¹³C/¹²C of acetic acid and the D/H values of acetic acid are not affected under a composite NMR experiment. The standard deviation of repeatability and standard deviation of reproducibility are comparable in wine vinegar and ABM and generally lower than those quoted in the official methods. This means that the validation parameters quoted in the official methods can also be applied to the ingredients of ABM. In addition, we found no changes in the isotopic values from wine to vinegar and to ABM, and from the original must to the ABM must, providing experimental evidence that reference data from wine databanks can also be used to evaluate the authenticity of vinegar and ABM.

Cystic fibrosis in adults: short-term and long-term reproducibility of the Brody score for lung morphology in low-dose MDCT scans

PURPOSE

The semi-quantitative Brody score measures the severity of cystic fibrosis (CF)-related lung disease. We investigated the short-term (28 - 60 days) and long-term (2 - 7 years) intra- and inter-observer reproducibility of the Brody score in low-dose multidetector row computed tomography examinations performed in inspiration (LDCTs) of adult CF patients.

MATERIALS AND METHODS

Composite Brody scores and respective underlying bronchiectasis, mucus plugging, peribronchial thickening, parenchymal opacity, and hyperinflation subscores were evaluated twice (time interval, 1 - 84 months) by each of 3 independent radiologists (1 - 20 years of professional diagnostic radiology experience) in LDCTs (4 - 64 rows, 120 KVp, 10 - 15  mAs/slice, CTDIw approx. 1.0  mGy, effective dose approx. 0.5  mSv) of 15 adult patients with CF-related lung disease (8 female, 7 male, age, 18 - 50 years, mean, 33 years).

RESULTS

The average reproducibility of the Brody score was within +/-7 % (range, 2 - 30 %) between radiologists, and +/-6 % (3 - 12 %) within radiologists (short-term, 28 - 60 days, 4 %, 0 - 12 %, long-term, 2 - 7 years, 12 %, 1 - 36 %). For the different subscores, the reproducibility was within +/-25 % (15 - 41 %) between radiologists and +/-23 % (12 - 46 %) within radiologists.

CONCLUSION

The Brody score shows high average inter-observer reproducibility in LDCTs of adult CF patients. The Brody score also demonstrates high average intra-observer reproducibility if subsequent assessments are made within 28 - 61 days. With time intervals of 2 - 7 years between subsequent evaluations, however, intra-observer reproducibility decreases. Respective subscores each demonstrate lower intra- and inter-observer reproducibility than does the composite Brody score.

Predicting the outcome of long-term care by clinical and functional indices: the role of nutritional status

In elderly subjects, past researches have already underlined the role of nutritional status as a basic factor able to influence the prognosis either in acute wards or in rehabilitation and long-term care settings. Aim of the study is that of retrospectively verify, through a multivariate analysis, the factors able to condition mortality in long-term care, paying particular attention to the nutritional status.

METHODS

The survey included 513 patients aged more than 65 years admitted to a long-term care unit during a three years period. Exitus within the first three months of hospitalization was considered the outcome variable, while baseline functional, cognitive, clinical and nutritional status were considered the independent variables eventually related to mortality.

RESULTS

The univariate analysis found that some variables were significantly correlated with the outcome: comorbidity, ADL, cognitive status, pressure sores, albumin, transferrin, CRP, mucoprotein, cholesterol, cholinesterase, MAMC and MNA. The predictive value of the block model of the logistic regression analysis was 77.9% (specificity = 85.3%, sensitivity = 63.9%). With the forward stepwise analysis only MNA, cholinesterase, CRP and mucoprotein were considered in the final model. In this case the predictive value of the model was 79.3% (specificity = 84.6%, sensitivity = 69.46%).

Obesity in the elderly

Obesity is a prevalent health disease among the elderly as it contributes to the early onset of chronic morbidity and functional impairment and is also related to premature mortality. The prevalence of sarcopenic-obesity increases too with age in each sex leading to a significantly higher prevalence of physical impairment and disability, as well as higher prevalence of metabolic syndrome. We observe a natural phenomenon (ageing) and a complex world-wide illness (obesity) that should not be merely treated as the sum of the treatments for the elderly and for the obese. The balance between the potential benefits of treatment interventions, reducing premature morbidity and mortality, and the impact on quality of life in old age may be different from young and adult age in case of obesity and need to be seriously considered.

Potential impact of a 32-channel receiving head coil technology on the results of a functional MRI paradigm

PURPOSE

The authors investigated the potential of a 32-channel (32ch) receiving head coil for functional magnetic resonance imaging (fMRI) compared to a standard eight-channel (8ch) coil using a motor task.

MATERIAL AND METHODS

Brain activation was analyzed in 14 healthy right-handed subjects performing finger tapping with the right index finger (block design) during two experimental sessions, one with the 8ch and one with the 32ch coil (applied in a pseudorandomized order). Additionally, a phantom study was performed to compare signal-to-noise ratios (SNRs) of both coils.

RESULTS

During both fMRI sessions, analysis of motor conditions resulted in an activation of the left "hand knob" (precentral gyrus). Application of the 32ch coil obtained additional activation clusters in the right cerebellum, left superior frontal gyrus (SMA), left supramarginal gyrus, and left postcentral gyrus. The phantom study revealed a significantly higher SNR for the 32ch coil compared to the 8ch coil in superficial cortical areas located near the surface of the brain.

CONCLUSION

The 32ch technology has a potential impact on fMRI studies, especially in paradigms that result in activation of cortical areas located near the surface of the brain.

Multidisciplinary approach to obesity

Obesity, associated with morbidity and mortality, is a complex disorder, characterised by an increase in fat mass (FM). Most authors agree in considering essential an integrated treatment made up of nutritional intervention, physical reconditioning programme and cognitive-behavioural psychotherapy. However, the feasibility is problematic and data in literature confirming the validity of this approach are poor.

AIM

To verify the efficacy of a multidimensional approach (Nutritional Psycho-Physical Reconditioning - NPPR) in obesity treatment.

METHODS

All patients admitted from June 2002 to June 2004 (464 subjects) ranged from 18 to 65 years old, with a body mass index (BMI) >30 kg/m2 were included in the programme. After the nutritional status evaluation a standard dietetic treatment (group N) or an integrated and multidisciplinary obesity treatment (group NPPR) was proposed.

RESULTS

In group NPPR treatment duration was significantly higher (142.6+/-26 vs 48.6+/-55 days - p=0.000), while the drop-out amount was definitely lower (5.5 vs 54.4%; p=0.000). Weight loss compared to the initial weight and the difference between initial and final FM resulted significantly higher in group NNPR. Subjects in NPPR obtained a higher increase in the distance covered in a 6-minute walk test (59.9+/-19 vs 40.5+/-17 m; p=0.04) and in muscular strength. State and trait anxiety, mood and quality of life scores improved in NPPR subjects while remained substantially stable in group N.

CONCLUSIONS

An integrated approach to obesity is the way to be pursued in order to obtain important and at least short-term results.

Perturbation of murine liver cyp-superfamily of isoforms by different combinations of pesticide mixtures

It was previously found that fenarimol, vinclozolin or acephate, three of the most used pesticides worldwide, provoked a marked perturbation of murine cytochrome P450 (CYP)-linked monooxygenases. Here, to more closely mimic human exposure, it was investigated whether different pesticide combinations administered i.p. in male Swiss Albino CD1 mice in single or repeated fashion (daily, for three consecutive days), affect CYP-dependent oxidations. The four simulated mixtures showed a complex pattern of CYP induction and suppression, especially after repeated injection. For example, while fenarimol alone was the most inducing agent--reaching a 79-fold increase over control in testosterone 2alpha-hydroxylase--followed by vinclozolin and acephate, coadministration with the former markedly reduced induction. Coadministration with vinclozolin, determined various positive and negative modulations. An increase of CYP2B1/2 and CYP3A1/2-associated oxidases and a decrease of ethoxycoumarin metabolism was observed in the acephate and vinclozolin mixture. An equivalent or reduced CYP expression, if compared to double combinations, was seen using the complete mixture. Taken as a whole, the unpredictability of the recorded effects with simple mixtures, shrinks the misleading extrapolation performed on a single pesticide. If reproduced in human, such changes, altering either endogenous metabolism or biotransformation of ubiquitous toxins, might have public health implications.

Perturbation of rat hepatic metabolising enzymes by folic acid supplementation

An adequate folate intake minimizes the risk of various cancers and other disorders such as vascular diseases and neural tube defects. However, meta-analyses revealed difficulties in supporting the relationship between folate intake and the risk of cancer. Interestingly, there have been no reports to date on the potential ability of folate to modulate xenobiotic metabolising enzymes (XMEs), the inhibition of bioactivating Phase-I XMEs and/or induction of detoxifying Phase-II XMEs being one of the most evoked cancer chemopreventive strategies. Here, several CYP-dependent oxidations were studied in liver sub-cellular preparations from Sprague-Dawley rats receiving rodent chow supplemented with folic acid daily, for 1 or 2 consecutive months. Using either specific substrates as probes of different CYP isoforms or the regio- and stereo-selective metabolism of testosterone as a multibiomarker, we found that folic acid markedly inactivated most of the Phase-I XME analysed; up to 54% for the CYP1A1-linked deethylation of ethoxyresorufin in males, and up to 86% for the testosterone 2alpha-hydroxylase (CYP2C11) in females, after 2 months treatment. The Phase-II marker glutathione S-transferase significantly increased (~107%) after 1 month of supplementation in females only. These changes, if reproduced in humans might have public health implications. These data suggest caution in performing folate chemoprevention trials before its overall toxicological characterization has been fully addressed.

Insulin secretion defects of human type 2 diabetic islets are corrected in vitro by a new reactive oxygen species scavenger

Oxidative stress is a putative mechanism leading to beta-cell damage in type 2 diabetes. We studied isolated human pancreatic islets from type 2 diabetic and non-diabetic subjects, matched for age and body mass index. Evidence of increased oxidative stress in diabetic islets was demonstrated by measuring nitrotyrosine concentration and by electron paramagnetic resonance. This was accompanied by reduced glucose-stimulated insulin secretion, as compared to non-diabetic islets (Stimulation Index, SI: 0.9 +/- 0.2 vs. 2.0 +/- 0.4, P<0.01), and by altered expression of insulin (approximately -60%), catalase (approximately +90%) and glutathione peroxidase (approximately +140%). When type 2 diabetic islets were pre-exposed for 24 h to the new antioxidant bis(1-hydroxy-2,2,6,6-tetramethyl-4-piperidinyl)decandioate di-hydrochloride, nitrotyrosine levels, glucose-stimulated insulin secretion (SI: 1.6+/-0.5) and gene expressions improved/normalized. These results support the concept that oxidative stress may play a role in type 2 diabetes beta-cell dysfunction; furthermore, it is proposed that therapy with antioxidants could be an interesting adjunctive pharmacological approach to the treatment of type 2 diabetes.

Quantitative evaluation of oxidative stress status on peripheral blood in beta-thalassaemic patients by means of electron paramagnetic resonance spectroscopy

High oxidative stress status (OSS) is known to be one of the most important factors determining cell injury and consequent organ damage in thalassaemic patients with secondary iron overload. Using an innovative hydroxylamine 'radical probe' capable of efficiently trapping majority of oxygen-radicals including superoxide we measured, by electron paramagnetic resonance (EPR) spectroscopy, OSS in peripheral blood of 38 thalassaemic patients compared with sex-/age-matched healthy controls. Thalassaemic patients showed sixfold higher EPR values of OSS than controls. Significantly higher EPR values of OSS were observed in those with a severe phenotype (thalassaemia major, transfusion-dependent) with respect to mild phenotype (sickle-cell/beta-thalassaemia, not transfusion-dependent) or thalassaemia intermedia. In patients with thalassaemia major, EPR values of OSS were positively correlated with serum ferritin and with alanine aminotransferase levels. In patients with sickle cell/beta-thalassaemia, there was no correlation between EPR value of OSS and all parameters considered. The type of chelating therapy (desferrioxamine or deferiprone) did not have an effect on EPR value of OSS. In conclusion, EPR 'radical probe' seems to be a valid innovative method to determine total OSS in patients affected by thalassaemia and might be used for evaluating new strategies of chelation, new chelators, or the efficacy of antioxidant formula.

CYP superfamily perturbation by diflubenzuron or acephate in different tissues of CD1 mice

This work aimed to investigate whether the insecticide acephate (125 or 250 mg/kg b.w.) or diflubenzuron (752 or 1075 mg/kg b.w.), two of the most widely used pesticides worldwide, impairs CYP-linked murine metabolism in liver, kidney and lung microsomes after repeated (daily, for three consecutive days) i.p. administration. The regio- and stereo-selective hydroxylation of testosterone was used as multibiomarker of different CYP isoforms. Both gender and tissue specific effects were observed. Lung was the most responsive tissue to induction by lower diflubenzuron dose, as exemplified by the marked increase of testosterone 7alpha-hydroxylation (CYP2A) (up to 13-fold) in males. Higher dose produced a generalized inactivation. At the lower dose acephate induced 6beta- (CYP3A1/2, liver) as well as 2beta- (CYP2B1/2, kidney) hydroxylase activities ( approximately 5 and approximately 4-fold increase, respectively) in males. In females, a marked suppression of the various hydroxylations was observed. At 250 mg/kg of acephate, animals did not survive. Induction of the most affected isoforms was sustained by immunoblotting analysis. Corresponding human CYP modulations might disrupt normal physiological functions related to these enzymes. Furthermore, the co-mutagenic and promoting potential of these pesticides, phenomena linked to CYP upregulation (e.g. increased bioactivation of ubiquitous pollutants and generation of oxygen free radicals) are of concern for a more complete definition of their overall toxicological potential.

Genetic and metabolic effects of gluconasturtiin, a glucosinolate derived from cruciferae

It is thought that induction of detoxifying phase-II drug metabolizing enzymes or inhibition of bioactivating phase-I by phytoalexins could protect against mutagens and neoplasia. In the search for potential naturally occurring molecular chemoprevention agents, particular attention has been devoted to isothiocyanates, which are breakdown products-via myrosinase-of glucosinolates such as gluconasturtiin (GNST), a natural constituent of cruciferae. Here, we first investigated the ability of GNST to modulate metabolizing enzymes in male Swiss Albino CD1 mice injected by gavage (24 mg/kg or 48 mg/kg b.w.) with GNST either in single or repeated (daily for four consecutive days) dose. Using selected probes to various cytochrome P450 (CYP) isoforms, a marked and generalized decrease of CYP content, NADPH-(CYP)-c-reductase and various CYP-linked monooxygenases (measuring CYP1A1, CYP2B1/2, CYP3A1/2, CYP1A2 and CYP2E1), was observed in hepatic, renal and pulmonary subcellular preparations (up to approximately 66% loss, liver). Similar behavior was recorded using the regio- and stereo-selective hydroxylation of testosterone as multibiomarker (CYP2A1 and CYP2B9, up to approximately 96% loss), as well as with the phase-II marker glutathione S-transferase (up to approximately 50% loss, liver). We also performed genotoxicity investigations, using the diploid D7 strain of yeast Saccharomyces cerevisiae as a biological test system. GNST was able to significantly induce point reverse mutation in growing cells without myrosinase, thus suggesting either a direct GNST or a CYP-linked metabolite role in the genotoxic response. On the contrary, in suspension test, the addition of myrosinase significantly increased mitotic gene conversion, probably due to the formation of GNST-derived phenylethyl isothiocyanate (PEITC) breakdown product. Taken together, our data suggest that GNST exerts a dual effect: while strongly inhibiting the microsomal (bioactivating) metabolism, GNST also possesses genotoxic activity. This concomitant mutagenic activity underlines the necessity of overall toxicological characterization of this (or any other molecule) prior to mass chemopreventive use.